Winter Stress

Winter weather can be responsible for stress that compromises a horse's health. The good news is that we, as caretakers, can alleviate that stress or even prevent it from occurring in the first place. Of course for some animals, such as show horses, one season is pretty much like another. They are housed in heated barns and are kept under blankets except when they are performing. The same isn't true of trail horses which are "put up" for the winter or for racehorses in certain parts of the country which are expected to perform as well in the cold of winter as they do in the heat of summer, or for horses which show, then are put outside. Those horses merit special concern and attention.

The prime source of winter stress for many horses is neglect--intentional or otherwise. It is easy to provide loving care for the horse, for example, when we are riding every day and want to make certain that he is fit and remains in good health so that we can participate full measure in our chosen recreational pursuit.

However, when the season ends, all too often horses are turned out to pasture and forgotten.

One of the first aspects of care that often is neglected involves the feet. Farriers around the country can tell horror stories of shod horses being turned out to pasture in early winter and shedding their shoes only when the hooves become so long that they break off. Unfortunately for the horse, this breaking off frequently involves more than just excess growth. It can involve the sensitive inner part of the hoof to the point where the horse is lame and his ability to be ready for spring riding is compromised.

There is no doubt that hooves grow more rapidly during the warm summer than they do during the cold winter. But, the fact remains, they do still grow during the winter months. In addition, the horse now often is traveling on hard, uneven, frozen ground that tends to take a heavier toll in the way of cracks and breaks.

It is very easy to prevent this particular type of winter stress: Have the shoes removed and the hooves trimmed before turning the horse out for winter. Second, have the farrier trim those feet on a regular basis, even though there might be a greater interval between trims than during the summer months. Not only does this prevent a form of winter stress, but it also insures that when a new riding season rolls around, the horse will have sound hooves that will be capable of holding a shoe.

The Need For Feed

Lack of proper winter nutrition also can be a form of winter stress. All too often wintering horses are tossed some hay once a day, with the thought being that it will take care of all nutritional needs. Often it does not.

We first must remember how a horse's digestive system works. For starters, the horse is an animal with an inordinately small stomach compared to the rest of its body. The capacity of a horse's stomach will range between eight and 19 quarts, depending on the size of the animal. This means that the horse, if left to its own devices, will eat frequently, but only consume a little food at a time. The horse is a grazing animal, and its digestive system is designed to convert grass and hay into energy--even body heat.

One of the reasons a horse eats small amounts frequently, in addition to the small size of the stomach, is that food remains in the stomach only about 15 minutes before it begins moving into the small intestine. The small intestine is the site for a major portion of nutrient absorption. It is there that soluble carbohydrates are digested to simple sugars and absorbed for use as energy. It takes somewhere between 30 to 90 minutes for food to pass through the small intestine, which, in the average horse, will be about 70 feet in length and will have a capacity of approximately 68 quarts.

Knowing the speed with which food passes through the stomach and small intestine can help us time our feeding program, particularly if the hay being fed is of inferior quality and we feel that grain supplementation is necessary. When that is the case, it is my practice to feed hay 10 to 15 minutes before feeding grain. (I feel this can help to slow the pace at which the grain is pushed through the stomach and small intestine.)

Next in line in the digestive process is the hindgut, which includes the cecum, large colon, small colon, and rectum. The horse's hindgut contains an active population of bacteria and protozoa. Microbes break down fibrous foods into fatty acids, which become an additional energy source. It takes between 36 and 72 hours for food to pass through the cecum and large intestine. In the average adult horse, the cecum is four feet long and has a capacity of 28 to 36 quarts. The large colon is 10 to 12 feet long and has a capacity of about 85 quarts. The small colon is 10 to 12 feet long and has a capacity of 15 quarts.

It becomes immediately apparent from the foregoing information that the horse's system is indeed designed to handle forage on a continuous basis. In other words, tossing hay once a day isn't the best feeding practice during the winter or any other time there isn't adequate grazing.

There is another problem with that scenario, one that can cause serious stress at feeding time. Horses are herd animals which live within a structured and ongoing pecking order. There is a dominant horse in every group. All the others will step aside when that horse approaches to eat or drink. However, the pecking order doesn't stop there. It continues on down the line until all horses in the group are accounted for.

What this means is that horses which are very low in the pecking order might be kept away from the food supply until it is diminished or even exhausted. They only will be allowed to pick up the scraps after others in the group have finished. It becomes instantly obvious that the nutritive needs of those horses will not be met if a limited amount of hay is fed once a day.

One solution is to feed the hay two or three times a day and to scatter it over a large area so that all horses in the group have equal access. An even better solution during the winter is to feed hay free choice. Even the most dominant of horses will leave a food supply once its stomach is full. Feeding round bales in a feeder on a free choice basis can be an answer, but there also are some inherent dangers because that type of hay, unless properly stored, is prone to the development of dust and mold.

If our hay supply is of inferior quality and we feel the need to supplement with grain, the problem with pecking order is exacerbated. Unless there are widespread feeding stations, one or two dominant horses in the group can wind up consuming all of the grain being fed. The best solution, if at all possible, is to feed a high-quality hay on a free choice basis that will satisfy nutritional needs.

Personally, I am of the opinion that a 50-50 mix of alfalfa and grass hay, fed either free choice or at least three times per day, can satisfy most of the horse's nutritional requirements. If you are in doubt as to how much to feed your horse or horses, you can turn to the National Research Council (NRC) for help at 202/334-2138 or search the web at The NRC has come up with recommendations for how much to feed a horse in varying states of exercise and age.

For example, the forage recommendation for the idle horse, such as one on winter pasture, is that it be fed 0.5% to 2% of its body weight per day and that concentrated feed should be fed at the rate of 0% to 0.5% of its body weight.

Of course, much will depend on the severity of the winter. Cold weather brings its own form of stress as the horse attempts to generate enough heat to provide body warmth during the coldest of weather. Geography will have a bearing. A horse's nutritive needs will be higher when it is minus 30 degrees Fahrenheit in Minnesota than they will be in some southern states where a below zero reading is rare.

Here again, free-choice hay can help alleviate cold weather stress by increasing body heat. For many years, old-time horsemen thought that if they fed corn during the winter months, it would generate body heat and help alleviate cold weather stress. In reality, the horse's body generates more heat from the ongoing fermentation process in the hindgut as the result of forage ingestion than it does from eating and processing corn. Corn, however, is high in energy.

If you must supplement your hay supply in the winter, one of the safest of grains to feed is oats. It contains 11%-12% crude protein, so it makes an excellent supplement if you are feeding alfalfa hay, which is high in protein. Also, the manner in which oat kernels are constructed makes them easy eating for horses, unless the animals are very young, very old, or have tooth problems. Oats are less vulnerable to molds than most other grains, and that makes them a safer part of your horse's diet.

An aspect of the horse's diet that should not be overlooked during the winter months involves minerals. Minerals in loose form should be offered on a free-choice basis. Many horse owners offer salt blocks that contain the necessary trace minerals. The only problem is that some horses won't spend enough time at the salt block to ingest the necessary amounts.

One thing to remember during the winter, however, is not to overfeed. Overfeeding can cause too much weight gain during the winter, which can lead to lam-initis in the spring. In addition, you will have a problem with trimming your horse's weight in the spring.

Other Considerations

One part of the horse's diet that often is overlooked during winter turnout is water. We might think that because the ground is covered with snow, the horse has no real need for an additional water supply. Not so. Yes, horses can and will eat snow. No, they can't get enough liquid into their systems that way. The best way to prevent winter stress from lack of water is a full water tank with a heater or, better yet, an automatic watering unit with a heating element so that fresh water is available at all times.

Climate determines other problems that need to be addressed. In the warmer, damper South, one must be on the alert all winter long for rain rot, the product of attacks by bacterial organisms. If unfound and unchecked, rain rot can result in loss of hair and irritation to the wintering horse.

Parasites, both internal and external, can be heavily implicated in winter stress. External parasites normally aren't much of a problem with the healthy, well-fed horse, but they can attack. The attacks will vary, area by area, and we should know which ones pose a threat in our area by talking to our veterinarian.

In colder climates, horse owners should be on the alert for the presence of lice and mites that attempt to make their homes and establish breeding factories beneath a thick, winter coat.

Whatever the case or climate, the important thing is that you do not just turn a horse out and forget about parasites or other problems. At every feeding, or on a daily basis if being fed free-choice, the horse should receive at least a visual examination. And every few days, each horse should be examined more closely by the rubbing of hands over the coat to make certain he is not being assaulted by microscopic creatures that can exacerbate or bring on winter stress.

Lack of shelter also can be a source of winter stress. Again, geography plays a role. This doesn't necessarily mean that the colder the climate, the more shelter required.

During our years in Minnesota, the healthiest horses on the place were those which ranged in a pasture with a dense growth of trees and brush. When the wind blew and the snow flew, this group of horses would disappear into the dense growth for shelter. When the sun emerged again, so did they, none the worse for wear. Their heavy coats of thick hair insulated their bodies against the cold.

However, not every pasture has a dense growth of trees and brush, and we might have to provide shelter of another type. One thing that is not needed to avoid winter stress from cold weather is a warm, insulated barn. There is, of course, nothing wrong with a warm barn, providing that it is well ventilated. Moisture buildup in an unventilated barn can be rapid. Lack of ventilation can be dangerous to the horse's respiratory system.

A case in point. Some years ago I constructed an indoor training arena in Minnesota, with box stalls on each side. There were cupolas on the roof for ventilation. At either end were large sliding doors that could be opened to welcome in summer breezes, but could be closed during inclement weather. The arena was not insulated and it was not heated. I soon discovered that the cupolas did not provide adequate ventilation dur-ing cold weather. In a matter of only a few hours after the big doors were closed on a cold winter day, moisture would form on the ceiling and shortly thereafter begin dripping on the horses in box stalls. The only solution was to leave both doors at least partially open no matter how cold it was outside.

A horse's best defense against cold weather is its long, thick coat of hair that it sports during the winter. He can walk around outdoors in total comfort even in sub-zero weather, if he has been properly fed.

The enemies of this winter comfort are rain and snow combined with wind. The hair is at its insulating best when it is dry and fluffed. It is at its insulating worst when it is wet and plastered against the horse's skin. When that happens, the hair is no longer capable of warding off cold and holding in body heat. The result is a horse which is thoroughly chilled.

One of the best solutions for preventing this is a three-sided shed. If the enclosed sides are to the north, east, and west, the horse will not only benefit from wind, rain, and snow protection, but also will be able to bask in the warmth of the sun on many winter days via the open southern exposure.

With a three-sided shed for protection, the horse can take shelter during rain or a snowstorm so that its insulating hair remains dry and fluffed. When the storm is over, the horse can emerge and be in total comfort even though the mercury has dropped to below zero.

Riding In Winter

There might be times when we wish to ride our horses during the winter months, even in the coldest of climes. If this is the case, we must take special care when cooling them out or we will be guilty of inflicting another form of winter stress.

If the horse has exerted itself to the point where it is wet with sweat beneath the saddle, we must use special care to prevent chilling. Sudden changes in body temperature, such as a cold wind blowing on a sweaty back, can have harmful results.

However, placing a heavy, insulated blanket on the horse immediately after unsaddling might be overkill. The heavy covering can trap moisture between skin and blanket, preventing the horse from drying. I have found it better to place a light blanket over the sweating horse in cold weather and lead it around until the hair is at least semi-dry. The exercise of walking helps keep the body from cooling too rapidly, and the light blanket protects from wind and cold while allowing moisture to evaporate.

When the horse's coat is dry, remove the now-damp light blanket and either turn the horse out or cover it with a dry blanket.

There are no real secrets to learn in dealing with winter stress. The horse owner's best allies are observation and common sense.

About the Author

Les Sellnow

Les Sellnow is a free-lance writer based near Riverton, Wyo. He specializes in articles on equine research, and operates a ranch where he raises horses and livestock. He has authored several fiction and non-fiction books, including Understanding Equine Lameness and Understanding The Young Horse, published by Eclipse Press and available at or by calling 800/582-5604.

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